Rust converting-and-inhibiting water-thinnable paint primer

Abstract

A water-thinnable primer effectively adherent to rusted metal and other substrates and to a variety of top coats has the form of an aqueous emulsion or aqueous suspension of a vinylidene chloride-vinylchloride copolymer and an alkyd resin, the alkyd resin being present in the amount of about 1/6 to 1/4 by weight of the vinylidene chloride-vinyl chloride copolymer, about 3 to 5% by weight of triethanolamine oleate as ionic surfactant, a drying accelerator composed of at least one polyvalent metal salt in an amount of about 1 to 4% by weight, about 8 to 15% by weight of a coalescing agent, and about 30 to 70% by weight of a pigment, all based on the weight of the total resin content of the primer.

I claim: 
     
       1. A paint primer which can be water thinned and is effectively adherent to rusted metal and other substrates and to a variety of top coats, comprising: an aqueous emulsion or aqueous suspension of a vinylidene chloride-vinylchloride copolymer and an alkyd resin, the aqueous emulsion or aqueous suspension having a pH of about 7 and the alkyd resin being present in an amount of about 1/6 to 1/4 by weight of the vinylidene chloride-vinylchloride copolymer, about 3 to 5% by weight of a triethanolamine salt as ionic surfactant, a drying accelerator composed of at least one polyvalent metal salt in an amount of about 1 to 4% by weight, about 8 to 15% by weight of a coalescing agent, and about 30 to 70% by weight of a pigment, all based on the weight of the total resin content of the primer. 
     
     
       2. A primer as defined in claim 1; wherein the vinylidene chloride-vinyl chloride copolymer is present in the amount of about 25 to 45% by weight of the primer. 
     
     
       3. A primer as defined in claim 1; wherein the vinylidene chloride-vinylchloride copolymer is present in the amount of about 35 to 45% of the primer. 
     
     
       4. A primer as defined in claim 1; wherein the coalescing agent is a polyglycol or a polyglycol ether. 
     
     
       5. A primer as defined in claim 1; wherein the pigment includes red oxide. 
     
     
       6. A primer as defined in claim 1; wherein the coalescing agent is methyl carbitol. 
     
     
       7. A primer as defined in claim 6; wherein the pigment includes red oxide. 
     
     
       8. A primer as defined in claim 6; wherein the alkyd resin contains about 36% phthalic anhydride. 
     
     
       9. A primer as defined in claim 1; further including a non-ionic surfactant. 
     
     
       10. A primer as defined in claim 1; further including a thickener. 
     
     
       11. A primer as defined in claim 1; further including a freezing stabilizer. 
     
     
       12. A primer as defined in claim 11; wherein the freezing stabilizer is propylene glycol. 
     
     
       13. A primer as defined in claim 1; wherein the primer is free of oxalic acid, tannic acid and phosphoric acid. 
     
     
       14. A primer as defined in claim 1; wherein the primer is free of acidic chelating agents. 
     
     
       15. A primer as defined in claim 1; wherein the primer has a pH in the range 6.5-7.5. 
     
     
       16. A primer as defined in claim 1; wherein the primer has a pH of 7.2.